Design of coplanar-waveguide-based elliptic filter using T-shaped defected ground structure

摘要

In this paper T-shaped Defected Ground Structure (DGS) has been proposed in the ground plane of the conventional coplanar-waveguide (CPW) structure. The T-shaped DGS has wider gap capacitance than the conventional dumbbell-shaped DGS, and provides a wide stop band and slow-wave characteristics. Thus, utilizing the above properties array of two T-shaped DGS structures has been introduced to obtain an elliptic low-pass filter (LPF). This proposed LPF is suitable for transferring low frequency signal up to 2.5 GHz satisfactorily. It provides sharp transition between pass- and stop-band with good sharpness factor, but almost 1.2 dB insertion loss in the pass-band. Therefore, the insertion loss in the pass-band is reduced with the help of compensated Hi-Lo coplanar waveguide (CPW) transmission line.